Condition responsive fuzing system



April 18, 1961 T. c. SMITH CONDITION RESPONSIVE FUZING SYSTEM Filed May 27, 1952 INVENTOR THOMAS C. SMITH ATTORNEYS 2,080,020 PatentedApr. 18, 1961 nice United States Patent 2,980,020 CONDITION RESPONSIV'E- FUZING SYSTEM Thomas C. Smith, Poughkeepsie, N.Y., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed May 27, "1952, Ser. No. 290,285

4 Claims. (Cl. 10270.2)

' the chine,

Accordingly, it is an object of the present invention to,

provide a fuzing system whereby the missile is caused to detonate under water without actual contact with the ships hull.

It is another object to provide means to establish. a

sufficient time delay previous to the detonation to' permit the missile to traverse its prescribed trajectory from its water entry'position to a point approximately underneath the ships keel. I V

It is still another object of the fuzing system to provide means causing the detonation of the missile, should it, during the course of its trajectory, impact a solid ob- Y ject either while in the air or under water. 1 a

It is an additional object to provide means coacting with the last mentioned means whereby the actual detonation of the missile is momentarilydelayed after impact, thus permittingthe missile to pass through a wall of the solid object before'the detonation occurs. f

It is a further object to provide an automatic selfcontained circuit-testing meansoperable after the missile has been launched whereby, if any defect be present in the electrical circuits. of the fuzing system, a premature detonation ,ofthemissile is prevented. Y

premature deton ation of the missile is prevented me- 1 chanically both prior to. launching and for a predetermined time after launching. i

Other objects in be o iousjrm detailed study .of the specification in the light of the-accompanying drawing, in which Figure 1 is a schematic diagram of the system,.and the following detailed description refers .to

tive arrangement ofl'the left half of Figure 1.-

Referring first to Figure 1, the actual detonation of v the'missile is :controlled ;by any one of three explosive trains 10,11, and 12.

The continuity between" these trains and their respective initiating means is mechanically interrupted by two plungers 13 and arranged transversely of the trains. H operated by means of hydrodynamic pressure entering through a passage 13 1. upon the entry of the missileinto water and acting against adistortable diaphragm 15;,-

V and plunger 14 is operated through theimeans'of a py'ro. -technicdevice 14a, more commonly referred toiasiani arrningfsquib whose ,gas'pressure upon initiation, acts against a distortablediaphragmilG. Y Switches 17 and 18,"

-.Itis a still further object toprovide meanslwhereby a" Plunger 13 is hydraulically plunger 13 has been caused to assume by conditions each having a plurality of contacts 17 and 18, a, b, and

c respectively, are operated in conjunction with the plungers 13 and 14 respectively, and provide a means for making and/or breaking various electrical circuitsto be described in detail hereinafter,

Included also in the system are two cold cathode diode tubes 19 and 20; four condensers, 21,22,23 and 24; an explosively operated single pole, single throw switch 25; and three primers, 26, 27 and 28 for initiating the firing of the detonators 13c, 13b, and 140 of the explosive trains 10, 11,'and 12 respectively...

From a general inspection of the connections to and from switch 17, it will be seen that the function of this switch is to connect either primer,26, or primers 27 and 28 to an activating source, the arrangement of the contacts of the switch being determined by the position external to the missile. Until the missile enters water primer 26 is connected through a normally closed contact of the switch 17 to one side of a source ofelectrical energy, condenser 22, and upon entry. into water thus activating plunger 13 as before mentioned, the normally closed contact is opened and two other contacts are: closed,

the first of which supplies electrical energy from one side of the same source to one side of primer 27 and the other of the newly closed contacts initiates the timing circuit 24), 24, and 43 for the primer 28.1 The necessity for opening the no'rmally'closed contact mentioned'above arises from the fact that it is entirely possible for primer 26 to act as a low resistance shunt across primer 27 after the missile has entered water thus dissipating the energy from condenser 22 to the extent that it is insufficient to initiate primer 27.

,rswitch 1-8 has a two-fold purpose and provides a means, first, to break the original parallel connections between condensers .21, Hand 23, and, second, to isolate each of the same. from each other and the pairof externalconductors 29, and 30 through which their initial.

electrical energy was received. Through this latter isolation feature, a premature or accidental discharge of the'condense'rs is prevented. Switch 18 'is activated throughmeans to be explained hereinafter when condenser 23 is charged to a voltage suflicient to .cause cold cathode diode tube 19to become conductive" indicia and reference numerals which appear on the draw mg, .and Figure '2-is a schematic diagramof analterna condenser 21 which condition is. aj'prime factor in con-J trolling the accuracy of .the timing circuit. -.Under these; I circumstances it may be said that the timing anddetona tion circuits within the missile are relatively independent- In the embodiment of the invention herein disclosed,

condenser 21 energizes a timing circuit at the time. of

water entry'including condenser 24- and cold cathode diode tube 20 which ultimately fires primerY28 after the missile is under water and does not experience .an impact, or it energizesthe primer 27 after an impact by the missile with an object under water. Condenser .22, on the other hand, energizes the remainder of the circuits testing means and/or fires primer 26 to detonate the missile after impact in air.

,Thus, it will be seen that, ,by theiprovision oftwo condensers, 211 and 22; each serving. as an independent sourceof electricalenergy,;;and two switches, 17 and 18, each; responsive to conditions external to the missile, any energyv I required for the initiation ,of 'primers, prior to the ini-. tiation of the timingcircuit fromeondenserZI and in-i cluding 20, 24, and 43, is taken only fromr-condenser22,"

thus permitting the maintenance of a;uniformvoltage'o'n of each other,

The fuzing system represented, schematically ingnigur'e 1'is activated by means of electrical cnergy received for a determinable time duration viapa pan conductors 29and 30 leading from the fuzefto an'externa lspurcepf i .DLC potential (not'shownLj'It isfalsoflp eierre for,

safety reasons that the charge is not imparted to the system until after the actual launching of the missile. Means for effecting the energization and timing the duration of the energization of an electrical circuit or circuits are Well known and form no part ofthis invention, per se, and are not described here.

The voltage applied to conductors 29 and 30 charges the condensers 21, 22, and 23 connected in parallel. The circuit arrangement to accomplish the charging of these condensers is wire 29 to one side of condenser 21; wire 31, contact a of switch 18, wire 32 to one side of condenser 22; and through resistor 35 to one side of condenser 23. The other side of 'thecircuit to these condensers is wire 30, contact 12 of switch 18, wire 33 to condensers 21 and 22; and contact of switch 18, wire 34 to condenser 23. The high resistance 35 leading to condenser 23 prevents that condenser from charging at the same rate as condensers 21 and 22. The latter condensers are charged to within predetermined voltage limits by the initial potential received via the connecting conductors 29 and 30 while condenser 23, due to the high resistance 35, ;is charged to a lesser degree and, in any event, to a voltage less than that required to effect breakdown of cold cathode diode 19. Part of the charge in condensers 21 and 22 is transferred to condenser 23 through a circuit from one side of condenser 21 via wire 31, contact a of switch 18 and wire 32, and one side of condenser 22 via wire 32, resistance 35 to one side of condenser 23. The circuit is completed from the other side of condensers 21 and 22 via wire 33, contacts b and c of switch 18, and wire 34 to the other side of condenser 23. i Connected in parallel with condenser 23, are the explosive switch and the arming squibb 14a, the latter con taining a pyrotechnic delay of short duration. A cold cathode diode tube19 is arranged in one side of the parallel circuit. Thus, when the condenser 23 has been charged to a sufficient voltage from the combination of potential sources previously described, the tube 19 will become conductive suflicient to actuate explosive switch 25, the contacts of-which quickly close, and the pyrotechnic delay 14a is initiated. Shortly thereafter diaphragm 16 deforms due to the accumulated gas pressure, thereby opening contacts 18a, b, and c of switch 18, and moving plunger 14 so that the detonator 14c and the portion 14b of the explosive train 10 contained within the Plunger 14 are in line with the explosive trains 12 and 10 respectively.

Attention is called at this point to the immediate closing of switch 25, and the delayed opening of switch 18 andmovement of plunger14. From a study of the. circuit arrangement in thedrawingto the leftofswitch 25,

improperly Wired switch, or otherdefect in the apparatus schematically represented in that part of drawing, may result in a prematureffiring of one or moreof' the primers 26, 27, and 28. However, since each of the explosive Continuing now the description of the normal operation of the fuzing system, an explanation of the three separate explosive trains, the firing of any one of which will sufiice to detonate the missile, will be made. Explosive train 10 functions upon impact by the missile with a solid object in air, train 11 functions upon an impact with an object under water, and train 12 functions without. an impact under water after the passage of a definite time period from the moment of water entry.

The first condition, that is a detonation of the missile following an impact in air, results from a firing of explosive train 10. This is accomplished by the activation of primer 26. From the prior description it will be seen that switch 25 has been closed and, after a short delay, plunger 14 has moved so that the section 14b of explosive rainlt) contained within the plunger is in line with the remainder of the train 10.

The circuit for the electrical firing of primer 26 is completed, upon the closing of impact switch 36 by the impact of the missile with a solid object in air, from one side of condenser 22, wire 37, closed switch 25,.Wl16 38, primer 26, wire 40, contact a of switch 17, wires 39 and 32 to the other side of the condenser 22. The primer 26 contains a short pyrotechnic delay means whereby the actual'firing of the detonator 13c and its associated explosive train 10, and the resultant detonation of the missile, is held back sufi'iciently to enable the missile to penetrate the wall of launching and at the instant of entry of the missile into water, plunger 13- and its associated switch 17 are moved by means of the external hydrodynamic pressure, effective via passage 13:: and acting upon distortable diaphragm 15. This device is only schematically presented here and is not described in detail since it forms no part of the present invention, per se. The movement of the plunger 13 places the 'detonator 13b of explosive train 11 in linewith the remainder of that train. The instantane ous movement of switch 17 associated with the plunger 13 opens contact a and closes contact b ofswitch 17'. The

shock of the impact of the missile with water mayor may not'activate impact switch 36, depending upon its sensitivity and thevelocity, weight, shape, and angle of water trains 10, 11, and 12 are elfectively blocked by a portion of either of the plungers 13 or 14, a premature detona tion of the missile is prevented. For example, it may be assumed that the impact jiggle switch 36 is defective or however, due to the explosivetrain It! being blocked by the as yet unmoved plunger 14 due to the delayed action of thepyrotechnic device 14pi'for operating that plunger.

In another example,.it maybeassurn ed that in addition: to switch 36 being defective, wires 39 and 41 were interimpact of the missile. If it does, primer '26 will be fired through the circuit previously traced after an impact in air.- The explosive train 10 will not be fired, however,.

of the missile isacoomplished by a subsequent closing of i the impact switch '36 resulting from an impact of the missile'with a solid object under the water. The electrical circuit is from one side of condenser 21, wire 37, closed switch 25, wire38,.closed impact switch 36, primer 27, wire 42, contact 17b ofswitch ll, and wires 41 and 31 to the other'side of condenser 21. The primer 27 contains a short pyrotechnic delay means whereby'the actualjfiring of the detonator 13b and its associated explosive train 11, and the'resultant detonation of the missile is heldback sufiiciently to enable the missile topenetrate the wall of the contacted object before dentonation occurs.

The third condition, that is, adetonation of the missile under water without impact withfia solid object, results from a firing'o'f explosivetrain 12 This is accomplished by the firing of primer 28. -'Ihe previous description has covered the closing of switch 25, and the movement of plunger 14 subsequentto launching but before entry of the missile into water.

movement of these plungers also results in the movement of the contacts of their-associated switches.

The movement ofplunger 13 closes contact 17c of circuit delays thebuildup of voltage in condenser 24.

When this condenser has been charged to a suificient voltage, a cold cathode diode tube 20,;arranged in series with primer 28 and across condenser 24, will become conductive sufficient to actuate and fire therprimer 28. -Since plunger 14fhas previouslybeen moved to a position whereby the detonator 14c,'contained within the plunger is in line with a remainder. of the'ex'plosive train 12, the

detonator 14c and its, associated explosive train 12 will be fired and the missile detonated. It will be obvious that tinder the last described arrangementt-he detonationof the missile has been accomplished after a definite time delay subsequent to'its entry into water and without'impact with an object. 1

While the arrangement according to Figure 1 is entirely practical, it will be obvious that the sensitivity of impact switch 36 must be adjusted within certain definite limits 7 which may not be wide enough for a specific use of the missile. Althouglrit may be sensitive enough to operate upon an impact of the missile with Water when entering the same it must not remain closed during water travel of the missile and on the other hand, the sensitivity must be suflicient to permitjclosure of the switch upon animpact of the missile with a solid object under water; If the switch is too sensitive, forces incidental to the deceleration ofthe missile while passing through water may be sufficient to hold the switch closed and, thus prematurely detonate the missile. If the switch is not sufiiciently sensitive, the missile will fail to detonate upon impact with a light target while in the air. I

In order to avoid these practical difficulties in adjust- Plunger 13, upon entry of the missile intowater, is moved as previously described. The

sources (condensers 21 and 22) for the various circuits,

6. but as has been before explained, plunger 13 is moved by external hydrodynamic pressure and detonator 13c moved out of line with the remainder .of the explosive train 10 and, at the same time, switch 17 is moved to open contact a and close contacts b and 6. Thus, even if primer 26 were to be fired by the circuit traced above, the missile would not be detonated, and, if switch 36 wereheld closed by the deceleration of the missile in the water, energy trom condenser 22 only would be discharged. When switch :17 is moved by plunger 13, condenser 21 is connected to the timing circuit governed by cold cath-. ode diode tube 20 as before, and primer 27 is connected through wire 38" and relatively less sensitive imp-act switch 36 to a circuit including this same condenser 21. Thus, it will be seen that the .Provision of two energy within the .missile fuzing system and two impact switches (36 and 36'.) operated according to deceleration producing conditions prevailing outside the missile, activation of one of the firing'trains 10- 12 inclusive in a predetermined manner, according to the prevailing conditions is accomplished. i

Various modification are contemplated and may obviously be resorted to without departing from the spirit and scope of theinvention, as only preferred embodiments thereof have been disclosed.

What is claimed is: a V

1. In a fuze for detonating the explosive charge of a missile, a first means fordetonating the charge comprising a primer," a detonator, and an explosive train, a plungercarrying said detonator, a circuitcomprising impact switch and said primer whereby the primer may be detonated by actuation of said impact switch,means for moving said plunger into said position in which said detonator is out of alignment with said train, a second means for detonating said explosive charge, comprising a second train and a primer, a second detonator carried by said plunger and moved into alignment with said second primer and said second train by said plunger, means to ignite said second primer, and a third means for detonating the charge a' predetermined time after movement of said second plunger. V V I 2. In a fuze for detonating the explosive charge of a missile, a first means for detonating the chargecomprising a primer, a detonator, and an explosive train, a first plunger carrying a portion of said train, a second plunger carrying said detonator, an arming squib having a time delay for moving said first plunger to said position in ing the sensitivity of'switch 36, the arrangement according to Figure 2 wherein two impact switches, 36 and 36 are provided, may be utilized. In this arrangement,

switch 36 is relatively more sensitive than switch 36', the latter being operable only when the missile impacts an' object under water while the former may be operated solelyby the missile penetrating relatively light material above the water.. Since eachswitch is connected to a' separate primer, the energizing circuit for which includes a different condenser, the continued closure of'the more i sensitive. switch 36 will not deenerg ize the source-of'potential for the other switch 36, and (see Fig. 1) a pre- I mature ,explosion of, primer 27- 'while the missile is travelling under Water is prevented.

Referring now to Figure 2, thetesting circuit'fromone side of condenser ll through wire 38 torelatively more sensitive impactswitch 36, wire 38, primer 26,'wire 40,

contact 17d-of switch 17 and wire 39 to the-other side of condenser221will function as before; Likewise the same circuitwill cause the detonation of -the missile after coni tacit with" a solid object in air.

linden the second condition where thejmissile 'is deto-' nated. following-an impact with a solid object under water, switch 36,.istclosed when the; missilecontacts. the water;

. for energizing said third primer a predetermined time after movement of said secondplunger.

which said portion of said train is in alignment with said train, a circuit including said arming squib and means for energizing said circuit to ignite said squib, a second circuit comprising an impact switch and said primer .whereby the primer may be detonated by actuation of said impact switch, means for moving said second plunger into said position in which said detonator is out of alignment with said train, a second means for detonating said explosive charge, comprising-a second train and a primer, a second detonator'carried by said second plunger and moved into alignment with said second-primer and said second train by said plunger, means to ignite said= second primer, and a third means for detonating. the

charge, comprising a third'primer, a third train and a. third detonator, said third detonator being moveable by said first plunger into a position in alignment with said train, a third circuit including the third primer and means 3. In a fuze for detonating the explosive charge of a mi'ssile, a first means for detonating the charge comprising a primer, a detonator, and anexplosive train, a first 7 gizing said circuit to ignite said squib, a testing switch, explosive means for closing said testing switch in parallel with said arming squib, whereby said energizing circuit will first ignite said explosive means and close said testing switch and thereafter detonatesaid arming squib, a second circuit comprising an impact switch said testing switch and said primer whereby the primer may be detonated by actuation of said impact switch, means corn municating with the exterior of said missile and adapted to be actuated by hydrodynamic pressure for moving said second plunger into a position in which said deton-ator is out of alignment with said train, a second means for detonating said explosive charge, comprising a second train, a primer, and a sec-ond detonator carried by said second plunger and moved into alignment with said second primer and said second train by said plunger, switch means actuated "by said second plunger to connect said impact switch, to said second primer, and a third means. for detonating the charge, comprising a third primer, a third train and a third detonator, said third detonator being moveable by said first plunger into a position in alignment withv said train, a third circuit including the third primer and means for energizing said third primer a predetermined time after movement of said second plunger.

4. In a fuze for detonating the explosive charge of a missile, a first means for detonating the charge comprising a primer, a detonator, and an explosive train, a first plunger carrying a portion of said train, a second plunger carrying said detonator, an arming squib having a time delay for moving said first plunger to a position in which said portion of said train is in alignment with said train,

a circuit including said arming squib and means for energizing said circuit to ignite said squib, a testing switch, explosive means -for closing said testing switch in parallel with said arming squib; whereby said energizing circuit will first ignite said explosive switch and close same and thereafter detonate said arming squib, a second circuit comprising an impact switch, said explosive switch and said primer 'whereby the primer may be detonated by actuation of said impact switch, means communicating at one side with the exterior of said missile and adapted to be actuated by hydrodynamic pressure for moving said second plunger into a position in which said detonator is outof alignment with saidtrain, a second means for detonating said explosive charge, comprising a second train and a primer, a second detonator carriedyby said second plunger and moved into alignment with said second primer and said second train by said plunger, a sec ond impact switch, switch means actuated by said second References Cited in the file of this patent UNITED STATES PATENTS 1,311,785' Wild rick July 29, 1919 1,789,158 Rudolph et a1. Jan. 13, 1931 1,841,983

Ruhlemann Jan. 19, 19312 

